People who commute to work by car, train or bus are more likely to have health worries than active commuters who walk or cycle, a study found.

Swedish researchers surveyed 21,000 workers aged 18 to 65, and those who commuted by car or public transit reported more everyday stress, exhaustion, missed work days and generally poorer health compared to the active commuters, according to the study published Oct. 30 in BMC Public Health.

"More research needs to be done to identify how exactly commuting is related to the ill health we observed in order to readdress the balance between economic needs, health, and the costs of working days lost," study author Erik Hansson from the Lund University in Sweden said in a statement.

The longer commute, the worse the health complaints for people who relied on public transport.

"We know that people who have a lot of demands and very little control over how they meet those demands are at a higher risk for negative health effects," said Dr. Redford Williams, professor of medicine and director of the Behavioral Medicine Research Center at Duke University. "And when you're relying on a train to get to work, it's totally out of your control most of the time."

The study does not reveal whether commuting by car or public transit actually causes health problems. But learning how to cope with the stress of commuting could help limit any negative health effects, Williams said.

"If you miss a train, ask yourself: is it important? Is it appropriate for me to be worried? Is the situation modifiable? Would it be worth for me to take the actions I would need to take to change it?" Williams said.

Commuting has also been linked to marital strife. But the current economy -- another source of stress for many -- can make it difficult for people to be picky about where they work relative to where they live.

"Obviously you have to weigh all of the factors involved," said Williams. "Probably anyone without a job would be well advised to take one wherever it was. But if you had a choice, you'd probably want to take the one with the shorter commute."